Steam generator

ABSTRACT

A steam generator operating in a closed loop configuration is disclosed. The steam generator includes two segregable compartments, a burner compartment and an economizer compartment. The periphery of the burner compartment includes a spiral passageway for venting air to the burner. The burning gases travel through a perforated sleeve and circulate about a plurality of interconnected, helically arranged water pipes, heating the water therein, and then enter an exhaust manifold for venting to the atmosphere. The water flow within the helically arranged pipes is counter to the flow of burning gases, which arrangement aids in producing superheated steam. The economizer compartment includes a plurality of concentric pipes spirally wound about a central cavity. The steam generated in the burner compartment and passed through an expander, such as a turbine, is vented into the outer of the concentric pipes. Water is introduced into the inner of the concentric pipes and flows in a direction reverse to that of the exhaust steam through the outer concentric pipes. In this manner, the water, prior to being conveyed to the burner compartment, is preheated by the exhaust steam. The air intake for the burner compartment passes through the central cavity within the economizer, around and about the plurality of concentric pipes, through tubes passing through the exhaust manifold and is vented into a passage about the burner itself. In this manner, the air intake is first heated by the exhaust steam passing through the outer of the concentric pipes and is further heated by the exhaust gases passing through the exhaust manifold. The exhaust system vented through the economizer is converted to a mixture of steam and water. The water is conveyed to a sump connected to a water pump which pumps the water into the inner of the sets of concentric pipes within the economizer. The burner within the steam generator includes a generator for producing a fixed frequency vibration within both the burner compartment and the economizer. The oscillations produced thereby increase heat transfer by reducing the boundary layer effects and act as a scrubber to inhibit deposition of particulate matter and corrosion about the outer surfaces of the pipes. Each of the pipes also includes means, such as a wire, helically wound about the pipe to aid in directing the surrounding medium about the full length of the pipe rather than just a limited portion of the pipe.

nited States Patent [191 Johnson 1972, abandoned.

[52] US. Cl 122/250 R, 122/24, 431/1 [51] Int. Cl. F22b 27/08 [58] Field of Search 122/24, 250; 431/1 [56] References Cited UNITED STATES PATENTS 2,351,163 6/1944 Thomas 122/379 2,748,753 6/1956 Sarrazin et al.. 122/24 2,878,790 3/1959 Paris et a1. 122/24 2,925,069 2/1960 Terpe 122/24 X 3,240,254 3/1966 Hughes 122/24 3,398,722 8/1968 Smykal, Jr. et a1. 122/250 3,630,175 12/1970 Reid, Jr. et a1. 122/250 Primary Examiner-Kenneth W. Sprague Attorney, Agent, or FirmWilliam C. Cahill [57] ABSTRACT A steam generator operating in a closed loop configuration is disclosed'The steam generator includes two segregable compartments, a burner compartment and an economizer compartment. The periphery of the burner compartment includes a spiral passageway for venting air to the burner. The burning gases travel through a perforated sleeve and circulate about a plurality of interconnected, helically arranged water pipes, heating the water therein, and then enter an exhaust manifold for venting to the atmosphere. The

water flow within the helically arranged pipes is counter to the flow of burning gases, which arrangement aids in producing superheated steam. The economizer compartment includes a plurality of concentric pipes spirally wound about a central cavity. The steam generated in the burner compartment and passed through an expander, such as a turbine, is vented into the outer of the concentric pipes. Water is introduced into the inner of the concentric pipes and flows in a direction reverse to that of the exhaust steam through the outer concentric pipes. In this manner, the water, prior to being conveyed to the burner compartment, is preheated by the exhaust steam. The air intake for the burner compartment passes through the central cavity within the economizer, around and about the plurality of concentric pipes, through tubes passing through the exhaust manifold and is vented into a passage about the burner itself. In this manner, the air intake is first heated by the exhaust steam passing through the outer of the concentric pipes and is further heated by the exhaust gases passing through the exhaust manifold. The exhaust system vented through the economizer is converted to a mixture of steam and water. The water is conveyed to a sump connected to a water pump which pumps the water into the inner of the sets of concentric pipes within the economizer. The burner within the steam generator includes a generator for producing a fixed frequency vibration within both the burner compartment and the economizer. The oscillations produced thereby increase heat transfer by reducing the boundary layer effects and act as a scrubber to inhibit deposition of particulate matter and corrosion about the outer surfaces of the pipes. Each of the pipes also includes means, such as a wire, helically wound about the pipe to aid in directing the surrounding medium about the full length of the pipe rather than just a limited portion of the pipe.

16 Claims, 7 Drawing Figures PATENTEB BET 8 74 Slim 1 BF 3 STEAM GENERATOR The present application is a continuation-in-part of my co-pending application Ser. No. 239,458, filed Mar. 30, 1972, entitled Steam Generator, now abandoned, and is related to US. Pat. application Ser. No. 807,800, filed Man 17, 1969, by the present inventor,

entitled Steam Generator now abandoned.

The present invention relates to steam generators, and more particularly, to closed loop steam generators having self-cleaning features to maintain effective and economical heat transfer between pipes and the surrounding medium.

Steam generators per se are very well known in the art. Each comprises a heat source, a means for directing the heat from the heat source about a plurality of pipes which convey water or a water and steam mixture, depending upon the proximity of the pipe to the heat source. The resulting steam is then conveyed to an expander to perform work. The exhaust steam from the expander may be vented to the atmosphere or it may be passed through a radiator to convert the steam into water, which water is conveyed back to the steam generator. There may also be performed a heat transfer function between the air fed to the heat source and the exhaust steam.

A primary object of the present invention is to pro vide a compact steam generator which may operate in a closed loop configuration.

Another object of the present invention is to provide a self-cleaning feature for a steam generator.

Yet another object of the present invention is to provide an efficient use of the heat generated by a heat source through a plurality of operations.

A further object of the present invention is to provide deflecting means for distributing the heat from the heat source about a maximum area of the steam generating components within the steam generator.

A still further object of the present invention is to provide a steam generator having a cool outer surface to reduce the safety hazard of the burner compartment.

These and other objects of the present invention will become apparent to those skilled in the art as the description thereof proceeds.

The steam generator comprises two discrete, but functionally related, heat exchange compartments: a burner compartment and an economizer compartment. Preheated air is circulated from the periphery of the burner compartment to the burner itself through a spiral passageway. The burning gases are directed about a plurality of different diameter, helically arranged sets of pipes and flow into an apertured exhaust manifold central to the burner compartment. The sets of pipes are serially connected in a quasi-spiral configuration with the smallest diameter set of pipes being adjacent the exhaust manifold. Means are included for directing the burning gases about each pipe of the sets of pipes.

The exhaust manifold includes a hollow passageway disposed intermediate the burner compartment and the economizer compartment through which the exhaust gases are vented. The economizer compartment includes a plurality of pairs of concentric pipes spirally wound about a central apertured cavity. The intake air is forced through the central apertured cavity, about the concentric pipes and to the periphery of the burner compartment through tubes disposed transverse the hollow passageway.

The water is pumped into the inner ones of the concentric pipes adjacent the central apertured cavity and flows spirally outwardly to the periphery of the economizer compartment. The water is subsequently conveyed to the burner compartment adjacent the apertured exhaust manifold and flows spirally outwardly therefrom toward the burner. The conversion of the water into steam occurs in the burner compartment, and the steam is conveyed to a conventional steam motor. The exhaust from the steam motor is conveyed to the outer ones of the concentric pipes at the periphery of the economizer compartment and flows spirally inwardly. In this manner, the water within the inner concentric pipes is preheated by the exhaust steam. The exhaust steam and water is collected adjacent the central apertured cavity and is returned to the water supply, whereby the steam generator operates as a closed system. The burner includes means for inducing resonance about the sets of pipes and the concentric pipes, which resonance increases the heat transfer by reducing the boundary layer effects and acts as a scrubber to maintain maximum heat transfer capability.

The present invention may be understood with more specificity and clarity with reference to the following figures, in which:

FIG. 1 illustrates a steam generator constructed in accordance with the teachings of the present invention.

FIG. 2 illustrates a cross section of the burner compartment of the steam generator.

FIG. 3 illustrates a pipe having a deflector disposed therearound.

FIG. 4 illustrates the positional relationship between a plurality of pipes having deflectors disposed therearound.

FIG. 5 illustrates the resonator disposed within the burner compartment.

FIG. 6 is a perspective view of another embodiment of a burner construction useful in the steam generator of the present invention.

FIG. 7 is a plan view, partly in section, of the burner embodiment of FIG. 6.

Referring to FIG. 1, there is shown the preferred embodiment of the steam generator of the present invention. The steam generator is divided into two basic functional units, a burner compartment 1 and an economizer compartment 2.

The constructional details of the burner compartment 1 may be understood with more clarity with reference to FIG. 2 in conjunction with FIG. 1. The burner compartment 1 includes an outer housing 39, enclosing a burner 22 and the sets of pipes 19, 20, and 21 wherein steam is generated. Air is conveyed into the envelope defined by housing 39 and enters a spiral-shaped passageway 46 at inlet 47. The air travels in a spiral path to burner 22 located at the outlet 48 of the spiral passageway 46. The burning gases and heated air emanating from burner 22 enters a cavity 7, which cavity is defined by the inner surface of spiral passageway 46 and perforated sleeve 50. The perforated sleeve 50 includes a plurality of openings 51, each of the openings 51 being partially covered by a deflector 52 extending into cavity 7. The purpose of deflectors 52 is that of changing the direction of flow of the burning gases. The change in direction of the burning gases slows down their velocity and effects a better heat transfer between the burning gases and the sets of pipes 19, 20, and 21.

Interior to perforated sleeve 50 are three sets of steam pipes 19, 20, and 21. Each of the sets of pipes are helically disposed about a first central cavity 3 and extend outwardly therefrom to perforated sleeve 50. The sets'of pipes 19 immediately adjacent the first central cavity 3 are of a smaller diameter than set of pipes 20. Similarly, the set of pipes 21 immediately adjacent perforated sleeve 50 are of larger diameter than set of pipes 20. The flow of burning gases is directed inwardly from perforated sleeve 50 to the first central cavity 3, while the flow of water and/or steam within sets of pipes 19, 20, 21 is from the inner set of pipes 19 to the outer set of pipes 21. In operation, the water contained within the three sets of pipes is converted to steam within these sets of pipes and, to accommodate the volumetric expansion of steam over water, the larger pipes will tend to compensate for the volumetric increase without an undue pressure increase.

The exhaust gases flow into the first central exhaust 3 through a plurality of openings 53 disposed therein. Thence, the exhaust gases flow through an exhaust manifold 5 disposed intermediate the burner compartment 1 and the economizer compartment 2. At the periphery of the exhaust manifold 5, the exhaust gases are vented into the atmosphere.

The steam generator within burner compartment 1 is conveyed by a steam pipe 24 from the set of pipes 21 to an overspeed valve 25. From the overspeed valve 25, a pipe 26 conveys the steam to an expander 27, which expander may be a turbine or similar steam motor. The exhaust steam from expander 27 is conveyed to the economizer compartment 2 through exhaust pipe 28.

The economizer compartment 2 includes a plurality of pairs of concentric pipes 9 spirally wound about a second central cavity 4. The exhaust steam from pipe 28 is conveyed to the outer pipes 10 of concentric pipes 9 adjacent the periphery of economizer compartment 2. The exhaust steam is conveyed within pipes 10 to the concentric pipes 9 immediately adjacent the second central cavity 4. A collector 13 is disposed adjacent the second central cavity 4 and is operably connected to outer pipes 10 to receive the exhaust steam and water contained therein. The exhaust steam and water within collector 13 is conveyed through return pipe 14 to a sump 30. Sump 30 is functionally associated with water pump 29 which pumps the accumulated water through water pipe 12 to the inner pipes 11 of concentric pipes 9 immediately adjacent the second central cavity 4. Thence, the water flows through inner pipes 11 to the periphery of the economizer compartment 2. An outlet water pipe 38 is connected to each of the inner pipes 11 at the periphery of the economizer compartment 2. The outlet water pipe 38 conveys the water to a set of pipes 19 immediately adjacent the first central cavity 3 within burner compartment 1.

As may be deduced from the above description, the exhaust steam flowing through outer pipes 10 flows counter to the water within inner pipes 11. Heat is transferred from the steam to the water, raising the temperature of the water The water is conveyed to the burner compartment, and the amount of heat transfer necessary to convert the water into steam is reduced because of the preheating step. The economizer compartment 2 also provides a second heat transfer function as will be described below.

The air for burner 7 is conveyed thereto by means of a blower 37 connected to an air intake pipe 8. Air intake pipe 8 conveys air to the second central cavity 4 with the air flowing into the economizer compartment 2 through a plurality of openings 54 disposed therein. The air flows through openings 54 of the second central cavity 4 into the economizer compartment 2. Within the economizer compartment 2, the air flows in and about the pairs of concentric pipes 9. The air outflow from economizer compartment 1 is through each of a plurality of tubes 6, which tubes are transverse to exhaust manifold 5. It will be observed that there is no direct communication between the exhaust gases within exhaust manifold 5 and the air within tubes 6. The air flows from tubes 6 into outer compartment 23 surrounding the air intake for burner 7. In operation, the air intake flowing from intake pipe 8 is initially heated within the economizer compartment 2 through contact with the outer surfaces of pipes 11, the latter having steam flowing therethrough. The air flowing through tubes 6 is also heated by the exhaust gases flowing about tubes 6 within the exhaust manifold 5.

Expander 27 includes a gear reduction unit 36 having a rotating shaft 35 extending therefrom. A pulley 34 is disposed on shaft 35 and drives a second pulley 32 via a belt 33. Pulley 32 is mounted on a shaft 31, which shaft 31 is operatively connected to the pumping mechanisms within water pump 29. Additional power takeoff means (not shown) are connected to expander 27 to perform work.

The junction between collector l3 and return pipe 14 may include a separator 15 for separating the steam from the water. In such an arrangement, the steam from collector 13 would flow through auxiliary pipe 16 to a pressure relief valve 17 through another auxiliary pipe 18 and thence to another radiator (not shown).

Referring to FIG. 3, there is shown a section of pipe 60, such as one of pipes 19, 20, or 21. A wire 61 is helically wrapped around pipe 60 in loose turns whereby adjacent turns are longitudinally spaced apart from one another. The pipes comprising the sets of pipes 19, 20, and 21 are coiled in helical fashion and arranged to be proximate one another but disposed by the thickness of the wire 61 as shown in FIG. 4. Such an arrangement of the coils provides several benefits. A primary benefit obtained is that of separating each of the coils from an adjacent one whereby the burning gases are not restricted from flowing about each of the coils due to an extended contact between the surfaces of two adjacent coils. A second benefit obtained is that the wires 61 surrounding each of the pipes 60 tend to deflect the burning gases along the longitudinal axis of the pipe to effect a more even distribution of the burning gases and prevent the emergence of hot and cold spots. Without the presence of wires 61, the water within the pipes 60 might be converted into steam at one point with condensation occurring at another point further along the flow of the steam within pipe 60. A tertiary benefit is that of being able to control the physical point within the sets of pipes 19, 20, and 21 at which the heated water is converted into steam as there is essentially uniform heating taking place from the periphery of the burner compartment 1 to the first central cavity 3. This physical point may be determined by controlling the temperature of the water and the intensity of burner 7.

As shown in FIG. 4, the wire 61 may be wrapped for one or more turns about one of pipes 60 and thence for one or more turns about an adjacent pipe 62. The effect of wire 61 so wrapped is not diminished and has a further advantage of tying the coils within the sets of pipes to one another to make a more unitary structure. In either wire arrangement, there will be a plurality of apertures and passageways immediately adjacent each and every pipe to permit effective and continuous heat transfer between the burning gases and the full length of pipes 60 and 62.

FIG. 5 illustrates apparatus which generates a tone of a predetermined frequency within both the burning gaseous medium and the air intake medium. At the burner 7 within burner compartment 1, a truncated cone 41) is disposed within the flow of gases. The gases enter through the base 49 of cone and exit through an aperture 43 at the apex of cone 40. A shroud 44 partially extends about base 49 and is secured thereto. An apertured plate 41 having a diameter approximately equal to the diameter of base 49 is secured to the circular periphery of shroud 44. Aperture 42 within plate 41 is concentric with and approximately the same size as aperture 43 of cone 40. The displacement of plate 41 from base 49 along the longitudinal axis of cone 40 is such that aperture 42 is approximately coincident with aperture 43. A further aperture 45 is formed by the ends of shroud 44, base 49, and the periphery of plate 41. The envelope defined by the shroud 44, plate 41 and the outer surface of cone 40 is a resonating chamber. A flow of air or gas is directed through the hollow cone 40 from the base 49 through aperture 43. Such an air flow will generate a tone of a specific frequency, the frequency, being dependent upon the dimension and configuration of the cone, the resonating chamber, and the apertures 42 and 43.

In operation, the tone generator shown in FIG. 5 is disposed within the burner compartment 1 as part of the burner 7. The burning gases of burner 7 generate the requisite air flow for the tone generator. The tones generated permeate the burner compartment 1 and increase heat transfer by reducing the boundary layer effects and act as a scrubber in removing the depositions of foreign matter on the surfaces of sets of pipes 19, 20, and 21. Thereby, the tone generator aids in maintaining an efficient heat transfer between the medium surrounding sets of pipes 19, 20, and 21 and the outer surface of these pipes. Similarly, the tone generated is also radiated into the air intake to reduce the boundary layer effects and performs a scrubbing action about the outer surfaces of the concentric pipes 9 within economizer compartment 2. The generated tone passing through outer chamber 23 and tubes 6 also tend to reduce the boundary layer effects and maintain their respective surfaces free of deposition of foreign matter and corrosion.

The exact frequency desired from the tone generator is dependent upon the size, number and effective resonance capability of the burner compartment 1 and economizer compartment 2. In a like manner, the intensity of the tone generated is a function of the attenuation experienced as the generated tone travels away from the tone generator. For these reasons, the exact tone and the intensity must be determined through empirical methods for different sized steam generators.

Referring now to FIGS. 6 and 7, another embodiment of a spiral path burner suitable for use in the steam generator of the present invention is shown.

Side plates and 111 are constructed in the shape of eccentric rings and are secured in spaced-apart relation by a wall 112. In the embodiment shown in the drawings, the wall 112 is formed by a plurality of curved overlapping vanes 125. The wall 112 forms a shroud having open ends 113 and 114 and which defines a combination area indicated in the drawings generally at the wall also has a cross section substantially comprising a 360 segment of a spiral about an axis 131. The wall 112 extends parallel to the axis 131 between side plates 110 and 111.

The vanes overlap and are slightly spaced to provide openings 132 therebetween. The openings 132 taper from point 134 to point 133 to form venturis with rectangular cross sections. These openings permit the entrance of secondary air between the vanes, as will be explained more fully hereinafter. A fuel nozzle or nozzles, such as that shown at 135, are positioned to direct gaseous fuel, such as propane, through openings 137 and 139 provided in a wall member 140 extending between the side plates 110 and 111. The wall member 140 is also conveniently positioned between ends 136 and 138 of the spiral segment formed wall 112. As the gaseous fuel emanates from the nozzles, such as nozzles 135, the stream of fuel passing through openings 137 and 139 induces the flow of air around the nozzles through the venturis 137 and 139, as indicated by the arrows 141 and 142. The fuel/air mixture is thus directed through the wall 112 substantially tangentially thereto and along a spiral path formed by the vanes 1 l5 125; the fuel/air mixture is initially ignited in any convenient manner, such as a glow or spark plug 145.

The combustion, having been started, is selfsustaining and the rapidly expanding and heating fuel- /air mixture accelerates as it traverses the interior of the combustion area 30 in a spiral path generally toward the axis 131. The high velocity induces turbulence in the mixture; the high velocity of the mixture also results in the induction of secondary air through the rectangular venturis 131 to assist in the complete burning of the fuel in the fuel/air mixture.

The tightening path of the fuel/air mixture, in addition to increasing velocity and turbulence, results in the recirculation and compression of heavier gases which are mixed with the primary air/fuel mixture at the recirculation is aided by a deflector 152. The openings or venturis 132 enable secondary air to be drawn into the burning mixture to insure complete burning of the fuel. As the burning fuel/air mixture follows a spiral path toward the center of the combustion area 130, the exhaust gases, and heated air resulting from the combustion, are ejected, parallel to the axis 131, as indicated by the arrow 147 and/or arrow 148. In the steam generator application of the present invention, the gases would, of course, be ejected in only one direction.

While the shroud comprising wall 112 is formed of fixed vanes 115 125, they may readily be made adjustable or self-adjusting by either appropriately hinging the blades or spring-biasing the blades to a preset position and permitting the induced vacuum caused by the fast moving fuel/air mixture on the interior surfaces of the vanes to change the openings between the vanes in accordance with the demand for secondary air. The

vanes 115 125 may also be replaced with vanes having no curvature, although the lack of curvature would undoubtedly reduce the efficiency of the spiral arrangement. Further, the wall 112 in the embodiment chosen for illustration may readily be replaced with a one-piece wall having a spiral cross section and having openings therein to permit entry of secondary air while vanes, creating a rectangular venturi, may be attached adjacent the openings. Such one-piece wall would provide the decreasing radius required to induce the spiral path followed by the fuel/air mixture as it enters the combustion area 130, while the openings would allow secondary air to be induced into the swirling, high velocity, burning fuel/air mixture.

While the principles of the invention have now been made clear in an illustrative embodiment, there will be immediately obvious to those skilled in the art many modifications of structure, arrangement, portions, the elements, materials, and components, used in the practice of the invention which are particularly adapted for specific environments and operating requirements without departing from those principles.

I claim:

1. A steam generator including a burner compartment and an economizer compartment, said generator comprising in combination:

a. a water pump for pumping water into said economizer compartment and receiving water from said economizer compartment;

b. first transporting means for conveying the pumped water through said economizer compartment adjacent a central cavity within said burner compartment;

0. a burner disposed within said burner compartment for generating burning gases;

d. guiding means for directing said burning gases toward said central cavity;

e. a tone generator energized by said burning gases for establishing pressure waves within said burner compartment and said economizer compartment;

f. second transporting means for conveying the water from adjacent said central cavity toward said burner, whereby the water is heated by said burning gases and converted to steam;

g. motive means responsive to the steam for producing work;

h. channeling means for collecting the exhaust steam from said motive means and conveying the steam to said economizer compartment;

. enveloping means surrounding said first transporting means for conveying the steam concentric with the water within said economizer compartment;

j. pipe means for returning the steam and water from said enveloping means to said pump; and

k. air intake means for introducing air to a central cavity within said economizer compartment and transporting the air through said economizer compartment to said burner compartment, whereby the water and air are preheated prior to entering said burner compartment.

2. The stcam generator as set forth in claim 1,

wherein said guiding means comprises wire helically wrapped about said second transporting means.

. 3. The steam generator as set forth in claim 1,

wherein said second transporting means comprises at least one set of helically arranged coils.

4. The steam generator as set forth in claim 1, wherein said air intake means includes a spiral passageway surrounding said burner.

5. A self-cleaning steam generator having water and air inputs, said steam generator comprising in combination:

a. a burner compartment including a burner for burning a gaseous mixture;

b. an economizer compartment for preheating water and air flowing into said burner compartment;

c. pipe means for conveying the water through said burner compartment to heat the water; and

d. a tone generator cooperating with said burner for producing periodic pressure waves, said pressure waves emanating in at least two directions from said tone generator, whereby said pressure waves traveling through said burner compartment and said economizer compartment reduce the bound ary layer effects and scrub said pipe means and the inside of said economizer compartment and thereby maintaining the heat transfer capability by inhibiting the build up of contaminants.

6. The steam generator as set forth in claim 5, wherein said tone generator includes means responsive to the flow of gaseous fluid for generating said pressure waves.

7. A steam generator having water and air inputs, said steam generator comprising in combination:

a. an economizer compartment for preheating the water and air;

b. a burner compartment including a burner for converting the water to steam;

c. an exhaust manifold central to said burner compartment for collecting the exhaust gases;

d. a plurality of interconnected helically coiled sets of pipes extending outwardly from said exhaust manifold;

e. an apertured sleeve disposed about said sets of pipes;

f. said burner being disposed exterior to said sleeve;

g. a spiral channel disposed about said burner on said sets of pipes for conveying the preheated air to said burner;

h. first pipe means for conveying the preheated water from said economizer to said set of pipes adjacent said exhaust manifold; and

. second pipe means connected to said set of pipes adjacent said sleeve for discharging the steam generated by said steam generator.

8. The steam generator as set forth in claim 7, wherein said exhaust manifold includes a heat exchange manifold intermediate said burner compartment and said economizer compartment.

9. The steam generator as set forth in claim 8, wherein said preheated air is conveyed from said economizer compartment to said burner compartment through tubes transverse to the flow of exhaust gases through said heat exchange manifold.

10. ln a steam generator including an economizer compartment for preheating water and air and a burner compartment for burning a gas in the presence of the preheated air to convert the preheated water to steam, the improvement comprising:

a. an exhaust manifold disposed central to said burner compartment for discharging the exhaust gases;

b. a plurality of interconnected, helically coiled sets of pipes extending outwardly from said exhaust manifold;

c. separating means disposed about each of the pipes with said sets of pipes for displacing said pipes from one another;

d. an apertured sleeve disposed about said sets of pipes;

e. said burner being disposed exterior to said sleeve;

f. transporting means for conveying the heated air to said burner; l

g. first pipe means for conveying the preheated water from said economizer to said set of pipes adjacent said exhaust manifold; and

h. second pipe means connected to said set of pipes adjacent said sleeve for discharging the steam generated by said steam generator.

ll. A self-cleaning steam generator including a source of water, and a source of combustible gaseous mixture, said steam generator comprising in combination:

a. a burner for burning the gaseous mixture,

b. a burner compartment for housing the burning gaseous mixture, said compartment including means connected to the source of water for transporting the water through said burner compartment to heat the water; and

c. a tone generating means disposed within said burner compartment actuated by the gaseous mixture prior to combustion of the gaseous mixture for producing periodic pressure waves within said burner compartment;

whereby, said pressure waves, traveling within said burner compartment, induce a scrubbing action about said transporting means to reduce the boundary layer effect and promote heat transfer from the burning gaseous mixture to the water.

12. The steam generator as set forth in claim 11, wherein said tone generating means comprises:

a. a hollow truncated cone having a base and a top;

b. a shroud secured to the base of said cone, said shroud extending about the base for less than the full circumference of the base; and

c. an apertured plate secured to said shroud, the aperture of said plate being generally coincident with the top of said cone.

13. The steam generator as set forth in claim 11,

wherein said periodic pressure waves emanate in all did. means for directing said periodic pressure waves into said economizer compartment; whereby, said periodic pressure waves, traveling within said economizer compartment, induce a scrubbing action about said conveying means to reduce the boundary layer effect and promote a heat transfer from the exhaust gases surrounding said conveying means to the water.

15. A steam generator including a burner compartment for burning a fuel-air mixture and an economizer compartment, said generator comprising in combination:

a. a water pump for pumping water into said economizer compartment and receiving water from said economizer compartment;

b. first transporting means for conveying the pumped water through said economizer compartment adjacent a central cavity within said burner compartment;

0. a burner disposed within said burner compartment for generating burning gases;

d. guiding means for directing said burning gases toward said central cavity;

e. a tone generator for establishing pressure waves within said burner compartment and said economizer compartment, said tone generating means actuated by said fuel-air mixture prior to combustion thereof;

f. second transporting means for conveying the water from adjacent said central cavity toward said burner, whereby the water is heated by said burning gases and converted to steam;

g. motive means responsive to the steam for producing work;

h. channeling means for collecting the exhaust steam from said motive means and conveying the steam to said economizer compartment;

i. enveloping means surrounding said first transporting means for conveying the steam concentric with the water within said economizer compartment;

j. pipe means for returning the steam and water from said enveloping means to said pump; and

k. air intake means for introducing air to a central cavity within said economizer compartment and transporting the air through said economizer compartment to said burner compartment, whereby the water and air are preheated prior to entering said burner compartment.

16. A self-cleaning steam generator including a source of water, and a source of a combustible mixture, said steam generator comprising in combination:

a. a burner for burning said combustible mixture,

b. a burner compartment for housing said burning combustible mixture, said compartment including means connected to the source of water for transporting the water through said burner compartment to heat the water; and

c. tone generating means disposed within said burner compartment actuated by said combustible mixture for producing periodic pressure waves within said burner compartment;

whereby, said pressure waves, traveling within said burner compartment, induce scrubbing action about said transporting means to reduce the boundary layer effect and promote heat transfer from the burning combustible mixture to the water. 

1. A steam generator including a burner compartment and an economizer compartment, said generator comprising in combination: a. a water pump for pumping water into said economizer compartment and receiving water from said economizer compartment; b. first transporting means for conveying the pumped water through said economizer compartment adjacent a central cavity within said burner compartment; c. a burner disposed within said burner compartment for generating burning gases; d. guiding means for directing said burning gases toward said central cavity; e. a tone generator energized by said burning gases for establishing pressure waves within said burner compartment and said economizer compartment; f. second transporting means for conveying the water from adjacent said central cavity toward said burner, whereby the water is heated by said burning gases and converted to steam; g. motive means responsive to the steam for producing work; h. channeling means for collecting the exhaust steam from said motive means and conveying the steam to said economizer compartment; i. enveloping means surrounding said first transporting means for conveying the steam concentric with the water within said economizer compartment; j. pipe means for returning the steam and water from said enveloping means to said pump; and k. air intake means for introducing air to a central cavity within said economizer compartment and transporting the air through said economizer compartment to said burner compartment, whereby the water and air are preheated prior to entering said burner compartment.
 2. The steam generator as set forth in claim 1, wherein said guiding means comprises wire helically wrapped about said second transporting means.
 3. The steam generator as set forth in claim 1, wherein said second transporting means comprises at least one set of helically arranged coils.
 4. The steam generator as set forth in claim 1, wherein said air intake means includes a spiral passageway surrounding said burner.
 5. A self-cleaning steam generator having water and air inputs, said steam generator comprising in combination: a. a burner compartment including a burner for burning a gaseous mixture; b. an economizer compartment for preheating water and air flowing into said burner compartment; c. pipe means for conveying the water through said burner compartment to heat the water; and d. a tone generator cooperating with said burner for producing periodic pressure waves, said pressure waves emanating in at least two directions from said tone generator, whereby said pressure waves traveling through said burner compartment and said economizer compartment reduce the boundary layer effects and scrub said pipe means and the inside of said economizer compartment and thereby maintaining the heat transfer capability by inhibiting the build up of contaminants.
 6. The steam generator as set forth in claim 5, wherein said tone generator includes means responsive to the flow of gaseous fluid for generating said pressure waves.
 7. A steam generator having water and air inputs, said steam generator comprising in combination: a. An economizer compartment for preheating the water and air; b. a burner compartment including a burner for converting the water to steam; c. an exhaust manifold central to said burner compartment for collecting the exhaust gases; d. a plurality of interconnected helically coiled sets of pipes extending outwardly from said exhaust manifold; e. an apertured sleeve disposed about said sets of pipes; f. said burner being disposed exterior to said sleeve; g. a spiral channel disposed about said burner on said sets of pipes for conveying the preheated air to said burner; h. first pipe means for conveying the preheated water from said economizer to said set of pipes adjacent said exhaust manifold; and i. second pipe means connected to said set of pipes adjacent said sleeve for discharging the steam generated by said steam generator.
 8. The steam generator as set forth in claim 7, wherein said exhaust manifold includes a heat exchange manifold intermediate said burner compartment and said economizer compartment.
 9. The steam generator as set forth in claim 8, wherein said preheated air is conveyed from said economizer compartment to said burner compartment through tubes transverse to the flow of exhaust gases through said heat exchange manifold.
 10. In a steam generator including an economizer compartment for preheating water and air and a burner compartment for burning a gas in the presence of the preheated air to convert the preheated water to steam, the improvement comprising: a. an exhaust manifold disposed central to said burner compartment for discharging the exhaust gases; b. a plurality of interconnected, helically coiled sets of pipes extending outwardly from said exhaust manifold; c. separating means disposed about each of the pipes with said sets of pipes for displacing said pipes from one another; d. an apertured sleeve disposed about said sets of pipes; e. said burner being disposed exterior to said sleeve; f. transporting means for conveying the heated air to said burner; g. first pipe means for conveying the preheated water from said economizer to said set of pipes adjacent said exhaust manifold; and h. second pipe means connected to said set of pipes adjacent said sleeve for discharging the steam generated by said steam generator.
 11. A self-cleaning steam generator including a source of water, and a source of combustible gaseous mixture, said steam generator comprising in combination: a. a burner for burning the gaseous mixture, b. a burner compartment for housing the burning gaseous mixture, said compartment including means connected to the source of water for transporting the water through said burner compartment to heat the water; and c. a tone generating means disposed within said burner compartment actuated by the gaseous mixture prior to combustion of the gaseous mixture for producing periodic pressure waves within said burner compartment; whereby, said pressure waves, traveling within said burner compartment, induce a scrubbing action about said transporting means to reduce the boundary layer effect and promote heat transfer from the burning gaseous mixture to the water.
 12. The steam generator as set forth in claim 11, wherein said tone generating means comprises: a. a hollow truncated cone having a base and a top; b. a shroud secured to the base of said cone, said shroud extending about the base for less than the full circumference of the base; and c. an apertured plate secured to said shroud, the aperture of said plate being generally coincident with the top of said cone.
 13. The steam generator as set forth in claim 11, wherein said periodic pressure waves emanate in all directions from said tone generator means; whereby, said pressure waves perform a scrubbing action upon the surfaces in the path of said pressure waves to reduce the boundary layer effect of these surfaces.
 14. The steam generaTor as set forth in claim 11, including a. an economizer compartment for preheating the water transported through said burner compartment; b. means for channeling the exhaust gases from said burner compartment through said economizer compartment; c. means disposed intermediate the source of water and said transporting means for conveying the water through said economizer compartment; and d. means for directing said periodic pressure waves into said economizer compartment; whereby, said periodic pressure waves, traveling within said economizer compartment, induce a scrubbing action about said conveying means to reduce the boundary layer effect and promote a heat transfer from the exhaust gases surrounding said conveying means to the water.
 15. A steam generator including a burner compartment for burning a fuel-air mixture and an economizer compartment, said generator comprising in combination: a. a water pump for pumping water into said economizer compartment and receiving water from said economizer compartment; b. first transporting means for conveying the pumped water through said economizer compartment adjacent a central cavity within said burner compartment; c. a burner disposed within said burner compartment for generating burning gases; d. guiding means for directing said burning gases toward said central cavity; e. a tone generator for establishing pressure waves within said burner compartment and said economizer compartment, said tone generating means actuated by said fuel-air mixture prior to combustion thereof; f. second transporting means for conveying the water from adjacent said central cavity toward said burner, whereby the water is heated by said burning gases and converted to steam; g. motive means responsive to the steam for producing work; h. channeling means for collecting the exhaust steam from said motive means and conveying the steam to said economizer compartment; i. enveloping means surrounding said first transporting means for conveying the steam concentric with the water within said economizer compartment; j. pipe means for returning the steam and water from said enveloping means to said pump; and k. air intake means for introducing air to a central cavity within said economizer compartment and transporting the air through said economizer compartment to said burner compartment, whereby the water and air are preheated prior to entering said burner compartment.
 16. A self-cleaning steam generator including a source of water, and a source of a combustible mixture, said steam generator comprising in combination: a. a burner for burning said combustible mixture, b. a burner compartment for housing said burning combustible mixture, said compartment including means connected to the source of water for transporting the water through said burner compartment to heat the water; and c. tone generating means disposed within said burner compartment actuated by said combustible mixture for producing periodic pressure waves within said burner compartment; whereby, said pressure waves, traveling within said burner compartment, induce scrubbing action about said transporting means to reduce the boundary layer effect and promote heat transfer from the burning combustible mixture to the water. 